Purpose: Compare intraocular pressure (IOP) control and complication rates of a second glaucoma drainage device (GDD) to diode transscleral cyclophotocoagulation (TSCPC) following failure of an initial GDD.
Patients and methods: Eyes with 1 GDD that required a second GDD or TSCPC for glaucoma control were included. Exclusion criteria were a cyclodestructive procedure before initial GDD, no light perception vision, or follow-up <1 year. Failure was defined as ≥1 of (1) reoperation for lowering IOP; (2) explantation of second GDD; (3) persistent hypotony; (4) use of oral carbonic anhydrase inhibitor for lowering IOP in the study eye; or (5) loss of light perception. Reoperation for lowering IOP included additional GDD implantation or additional cyclodestruction, except if additional cyclodestruction was within 6 months of the initial session.
Results: A total of 75 eyes (35 in second GDD; 40 in TSCPC) were included (mean follow-up, 25.5 mo). Both procedures lowered IOP [-11.4 mm Hg (±13.6) for second GDD and -7.8 mm Hg (±11.8) for TSCPC groups] and decreased the number of IOP-lowering medications at the last visit. The second GDD group had significantly greater mean survival time [45.0 mo (±4.2)] than the TSCPC group [26.5 mo (±2.8)] but significantly more postoperative complications (60% of eyes) and non-IOP-related procedures (40% of eyes) than the TSCPC group (20% for postoperative complications and 18% for non-IOP-related procedures).
Conclusions: Although both second procedures are efficacious in lowering IOP and number of IOP-lowering medications, TSCPC failed earlier, whereas a second GDD had significantly more complications.